MeTV is a broadcast network carried by a local TV station. It sounds like your local station dropped it. Comcast has no control of this and simply passes on what is broadcast.
on KOFY's website they are posting this: "MeTV’s upcoming over-the-air and Comcast Xfinity channel positions will be announced soon. To find MeTV in your area go to metv.com/wheretowatch and enter your zip code." I really miss MeTV and especially the Sci-Fi Saturday programs , it's a bummer they were dropped with no warning.